초록 ▼

An improved airfoil blade for aircraft propellers and the like which exhibits high aerodynamic performance and low far and near field noise levels at a minimum weight is provided with a novel high lift and high lift to drag cross-sectional airfoil shape characterized by a blunt, generally parabolic

An improved airfoil blade for aircraft propellers and the like which exhibits high aerodynamic performance and low far and near field noise levels at a minimum weight is provided with a novel high lift and high lift to drag cross-sectional airfoil shape characterized by a blunt, generally parabolic leading edge portion (10) which fairs into a pressure surface (15) characterized by a leading convex portion (20). For thickness ratios less than approximately 0.15, the pressure surface includes a concave trailing portion (25) at one end thereof, fairing into the leading convex portion (20) and at the other end thereof, terminating at a blunt trailing edge (35). The leading edge portion also fairs into a suction surface (30) which is convex along substantially the entire length thereof to the blade trailing edge.

대표청구항 ▼

An airfoil blade having along substantially the entire length thereof, a cross-sectional airfoil shape comprising a rounded, generally parabolic leading edge portion fairing into a pressure surface; said pressure surface having a leading convex portion fairing into a trailing portion; said leading e

An airfoil blade having along substantially the entire length thereof, a cross-sectional airfoil shape comprising a rounded, generally parabolic leading edge portion fairing into a pressure surface; said pressure surface having a leading convex portion fairing into a trailing portion; said leading edge portion also fairing into a convex suction surface; said pressure and suction surfaces merging into a blunt trailing edge; one of said airfoil shapes having a thickness ratio of 0.04, a maximum thickness at approximately 0.35 x/c and a maximum camber at approximately 0.5 x/c; another of said airfoil shapes having a thickness ratio of 0.06, a maximum thickness at approximately 0.34 x/c and a maximum camber at approximately 0.50 x/c; another of said airfoil shapes having a thickness ratio of 0.08, a maximum thickness at approximately 0.33 x/c and a maximum camber at approximately 0.50 x/c; another of said airfoil shapes having a thickness ratio of 0.12, a maximum thickness at approximately 0.32 x/c and a maximum camber at approximately 0.38 x/c; another of said airfoil shapes having a thickness ratio of 0.20, a maximum thickness at approximately 0.315 x/c and a maximum camber at approximately 0.30 x/c and another of said airfoil shapes having a thickness ratio of 0.30, a maximum thickness at approximately 0.310 x/c and a maximum camber at approximately 0.29 x/c wherein x/c is the dimensionless chord length of said airfoil shapes; all of said airfoil shapes having a trailing edge portion of a thickness equal to approximately 10% of the maximum shape thickness.